django-saml-sp 0.8.0

A Django application for running one or more SAML service providers (SP).

Installation

• pip install django-saml-sp
• Add sp to your INSTALLED_APPS setting

Local Test Application

Start the local SimpleSAML IdP

docker run -it --rm -p 8080:8080 -p 8443:8443 \
-e SIMPLESAMLPHP_SP_ENTITY_ID=http://localhost:8000/sso/local/ \
-e SIMPLESAMLPHP_SP_ASSERTION_CONSUMER_SERVICE=http://localhost:8000/sso/local/acs/ \
-e SIMPLESAMLPHP_SP_SINGLE_LOGOUT_SERVICE=http://localhost:8000/sso/local/slo/ \
kristophjunge/test-saml-idp

Bootstrap and run the local SP test app

python manage.py migrate
python manage.py bootstrap
python manage.py runserver

The test SAML IdP defines the following user accounts you can use for testing:

UID	Username	Password	Group	Email
1	user1	user1pass	group1	[e-mail]
2	user2	user2pass	group2	[e-mail]

Sustainsys Stub IdP

The bootstrap command also creates a stub IdP which authenticates via https://stubidp.sustainsys.com. This is a good option if you don't want to run your own local identity provider for testing.

Integration Guide

Django Settings

• AUTHENTICATION_BACKENDS - By default the Django authentication system is used to authenticate and log in users. Add sp.backends.SAMLAuthenticationBackend to your AUTHENTICATION_BACKENDS setting to authenticate using Django's User model. The user is looked up using User.USERNAME_FIELD matching the SAML nameid, and optionally created if it doesn't already exist. See the Field Mapping section below for how to map SAML attributes to User attributes.
• LOGIN_REDIRECT_URL - This is the URL users will be redirected to by default after a successful login (or verification). Optional if you set IdP.login_redirect or specify a next parameter in your login URL.
• LOGOUT_REDIRECT_URL - This is the URL users will be redirected to by default after a successful logout. Optional if you set IdP.logout_redirect or specify a next parameter in your logout URL.
• SESSION_SERIALIZER - By default, Django uses django.contrib.sessions.serializers.JSONSerializer, which does not allow for setting specific expiration dates on sessions. If you want to use the IdP.respect_expiration flag to let the IdP dictate when the Django session should expire, you should change this to django.contrib.sessions.serializers.PickleSerializer. But if you do not plan on using that feature, leave the default. Note: Django 4.1 forward now supports datetime session exipry using the default JSONSerializer.

SP Settings

• SP_IDP_LOADER - Allow you to specify a custom method for the SP views to retrieve an IdP instance given a request and the URL path parameters.
• SP_AUTHENTICATE - A custom authentication method to use for IdP instances that do not specify one. By default, sp.utils.authenticate is used (delegating to the auth backend).
• SP_LOGIN - A custom login method to use for IdP instances that do not specify one. By default, sp.utils.login is used (again, delegating to the auth backend).
• SP_LOGOUT - A custom logout method to use for IdP instances that do not specify one. By default, sp.utils.logout is used, which simply delegates to Django's auth.logout.
• SP_PREPARE_REQUEST - A custom prepare_request method to use for IdP instances that do not specify one. By default, sp.utils.prepare_request is used.
• SP_UPDATE_USER - A custom update_user method to use for IdP instances that do not specify one. By default, sp.utils.update_user is used, which updates user fields based on mapped SAML attributes when users are created, or when the attributes are set to always update.
• SP_UNIQUE_USERNAMES - When True (the default), SAMLAuthenticationBackend will generate usernames unique to the IdP that authenticated them, both when associating existing users and creating new users. This prevents user accounts from being linked to multiple IDPs (and prevents spoofing if untrusted IDPs can be configured).

URLs

The application comes with a URLconf that can be included, using any path parameters you want. The IdP is fetched by matching any URL parameters to the url_params field (or by some custom means via SP_IDP_LOADER above). For example:

path("<prefix>/sso/<idp_slug>/", include("sp.urls"))

Assuming the URL configuration above, and an IdP configured with url_params={"prefix": "my", "idp_slug": "local"}, the following URLs would be available:

URL	Description
/my/sso/local/	The entity ID, and metadata URL. Visiting this will produce metadata XML you can give to the IdP administrator.
/my/sso/local/acs/	The Assertion Consumer Service (ACS). This is what the IdP will POST to upon a successful login.
/my/sso/local/slo/	The Single Logout Service (SLO). The IdP will redirect to this URL when logging out of all SSO services.
/my/sso/local/login/	URL to trigger the login sequence for this IdP. Available programmatically as idp.get_login_url(). Takes a next parameter to redirect to after login. Also takes a reauth parameter to force the IdP to ask for credentials again (also see the verify URL below).
/my/sso/local/test/	URL to trigger an IdP login and display a test page containing all the SAML attributes passed back. Available programmatically as idp.get_test_url(). Does not actually perform a Django user login.
/my/sso/local/verify/	URL to trigger a verification sequence for this IdP. Available programmatically as idp.get_verify_url(). Does not perform a Django user login, but does check that the user authenticated by the IdP matches the current request.user.
/my/sso/local/logout/	URL to trigger the logout sequence for this IdP. Available programmatically as idp.get_logout_url(). Takes a next parameter to redirect to after logout.

You can also include sp.urls without any URL parameters (e.g. path("sso/", include("sp.urls"))) if only a single IdP is needed (it should have url_params={}).

Configuring an identity provider (IdP)

1. Create an IdP model object, either via the Django admin or programmatically. If you have metadata from your IdP, you can enter the URL or XML now, but it is not required yet.
2. Generate a certificate to use for SAML requests between your SP and this IdP. You may use the built-in admin action for this by going to the Django admin page for Identity Providers, checking the row(s) you want, and selecting "Generate certificates" from the Action dropdown. If you already have a certificate you want to use, you can paste it into the appropriate fields.
3. Give your IdP administrator the Entity ID/Metadata URL and ACS URL, if they need to explicitly allow access or provide you attributes.
4. At this point, if you didn't in step 1, you'll need to enter either the IdP metadata URL, or metadata XML directly. Saving will automatically trigger an import of the IdP metadata, so you should see the Last Import date update if successful. There is also an "Import metadata" admin action to trigger this manually.

Your IdP is now ready for testing. On the admin page for your IdP object, there is a "Test IdP" button in the upper right corner. You can also visit the .../test/ URL (see above) manually to initiate a test. A successful test of the IdP will show a page containing the NameID and SAML attributes provided by the IdP.